Continental for tires of yesteryear, still have a set of Grand Prix, in great shape from 1999. Lots of tread and sidewalls in great shape, though discolored. Really nice, lightweight tire. As they were old, I changed to the Krylion.
The Michelin Krylion 23 have been durable and reliable. The only complaint is they are a bit harsh on my steel bike over chip seal. No cuts, no flats. Not as light and responsive, nor as comfortable as the ZX.
Upgraded from Krylion to Schwalbe ZX. Full winter and spring with no issues, no punctures, even riding over newly paved road, PIA to remove the tar. Tires are still going strong.
So I bought a new set of ZX's for my new lightweight road bike. The experience has not been pleasant. 2 rides, 2 flats with cuts deep enough to ruin the tires. Ok, so I bought the silver sidewall, maybe, as Schwalbe states, the all black are better. Bought a set of black. On the way through town to the first ride with the new tires, a flat and another ruined tire. I have no idea why one set is still going strong after 8 months and 2 others are trash. I suppose it could happen to anyone, or then again, maybe it is poor quality control at Schwalbe, who knows. The roads here are relatively clean. Very little broken glass. More sharp stones than anything else. All of the ruined Schwalbe tires had large cuts through the casing, but nothing stuck in the tire (i.e. tacks, nails, wire, etc.). Schwalbe have not responded to my comments. I just can't afford to keep trying to find another durable set of ZXs, not to mention I have no confidence they will get me safely down a twisty descent. Too bad,they are light, soak up rough road, and they are grippy in the wet and dry. Next, Vittoria Open Pavé.
Tomorrow is the first ride with these tires. 100km is not enough to evaluate a tire. Others have reported good results. I hope for the best. They are certainly more difficult to mount on my HED Bastogne wheels. The ZX's went on with little drama. The Vittorias not so. Really a challenge.